Issue reading input data from 2D array - c

Question

I'm trying to make a matrix algebra program, so I began with a pre defined 3x3 matrix. Ran into some issues with the elements not being read properly into the 2D array so I isolated one . The issue is that the last number in a row is printed as the first element in the next row. i.e. array[1][2] is printed out as what array [2][0] is.
Again, if I have a 3x3 matrix where we go from 1 to 9, and I want the value at row 1 column 3 (which is 3), it'll give me 4. Same goes for row 2 column 3; the value is 6 but it gives me 7.
I've put in a print statement to show me the counter values before input and they're correct. Something is going on with the scanf I guess but I'm really stumped. Any help would be appreciated!
#include <stdio.h>
int matrix1[2][2];
void main(void)
{
int i = 0, j=0; //Row and column subscripts for the first matrix
//======================================================================================================//
//First Matrix
printf("This is for the first matrix");
for(i=0; i < 3; i++) //Start with row
{
for(j = 0; j < 3; j++)
{
printf("\nInsert the value at row %d, column %d: ", i+1,j+1); //+1 since array's begin at 0
printf("\ni is %d, j is %d", i,j); //Shows what elements the input will go into
scanf("%d", &matrix1[i][j]); //Enter value into row i column j
}
}
printf("\n\n%d", matrix1[1][2]); //test to see what's in the element
}

Answer 1

#include <stdio.h>
#define ROWS 3
#define COLS 3
int matrix1[ROWS][COLS];
void main(void)
{
int i, j; //Row and column subscripts for the first matrix
//================================================================================
//First Matrix
printf("This is for the first matrix");
for(i=0; i < ROWS; i++) //Start with row
{
for(j = 0; j < COLS; j++)
{
printf("\nInsert the value at row %d, column %d: ", i+1,j+1);
printf("\ni is %d, j is %d", i,j);
scanf("%d", &matrix1[i][j]);
}
}
printf("\n\n%d", matrix1[1][2]); //test to see what's in the element
}

Answer 2

I think You are confused with array index numbers and total number of elements in array.
For Example When You have array of 5 integers.
int ary[5] = {11,22,33,44,55};
`------------IN Memory-----------
| 11 || 22 || 33 | | 44 | | 55 |
------------------------------- `
0 1 2 3 4 <--------These are called Index numbers.
They always start with 0,Hence
they always end with(Total Number of elements - 1)
Hence From above explanation you either want to change the size of array
from int matrix[2][2] to int matrix[3][3];
OR
either change your for() loops to
for(i=0; i < 2; i++) //changed i<3 to i<2
{
for(j = 0; j < 2; j++) //changed i<3 to i<2
{
// your Code.....
}
}